keyboard problem with netbsd-5/xorg

Hi folks,
I've got a netbsd-5 system with a kernel from 19th Dec 2009, and bundled
xorg (vers 1.6.3) from the same date. The machine has a SuperMicro
X7DB8 motherboard with a PCI Radeon 4350 graphics card (internal ES1000
disabled).
When I run X (via startx), a ps2 keyboard has all the keycodes managled,
and is basically unusable. For example, the row of keys starting "a, s,
d, f, ..." return keycodes for "0, 1, 2, 3, ..." and the space bar acts
as caps lock. A USB keyboard works perfectly.
I'd really like to keep my DEC LK461 keyboard, so "use a different
keyboard" isn't a fix I'm willing to go for at this stage :)
I'll dig around for more details, but wanted to get this initial query
out to see if anyone else had seen similar problems and (even better!)
fixed them.
Cheers,
Simon.